title: Preparation of 211At-labeled humanized anti-Tac using 211At produced in disposable internal and external bismuth targets.
abstract: These studies describe the production and purification of 211At as well as the procedure for labeling humanized anti-Tac, the antibody to the alpha-chain of the IL-2 receptor (IL-2R alpha), which has been shown to be a useful target for immunotherapy. The optimized protocol combines the advantages of the two-stage dry distillation procedure with the astatination of trialkylstannyl substances as labeling compounds for proteins. The 211At was produced by bombarding either an external or a recently developed disposable internal bismuth target with alpha-particles from a Cyclotron Corporation CS-30 cyclotron. The 211At was found to contain less than 0.01% 210At. The production rate for the external target was 0.15 mCi +/- 0.056 microA(-1) h(-1) (n = 9) (5.55 MBq mcroA[-1] h[-1]). The production rate for the internal target was 0.44 +/- 0.14 mCi microA(-1) h(-1) (n = 16) (16.28 MBq mcroA[-1] h[-1]).
authors.affiliation: National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: U P
authors.initials: UP
authors.lastname: Schwarz
authors.forename: P
authors.initials: P
authors.lastname: Plascjak
authors.forename: M P
authors.initials: MP
authors.lastname: Beitzel
authors.forename: O A
authors.initials: OA
authors.lastname: Gansow
authors.forename: W C
authors.initials: WC
authors.lastname: Eckelman
authors.forename: T A
authors.initials: TA
authors.lastname: Waldmann
mesh_terms: D001246:Astatine / Q000737:chemistry*; D001729:Bismuth / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D017357:Cyclotrons; D004355:Drug Stability; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D011868:Radioisotopes; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000494:pharmacology; D015375:Receptors, Interleukin-2 / Q000378:metabolism*
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D015375:Receptors, Interleukin-2; D001729:Bismuth; D001246:Astatine